In this video guide, Monty Don shows you how to fill any gaps in your borders with half-hardy annuals, which will provide colour through to the first frosts. Check out his favourites: fragrant tobacco plants (Nicotiana sylvestris), Cleome hassleriana ‘Cherry Queen’ and ‘White Queen’, and the elegant white Cosmos bipinnatus‘Purity’, then give them a try yourself. Many half-hardy annuals should still be available to buy in garden centres.